Precision caliper gauges have been known and widely used by craftsmen to measure inside diameters of screw threads, O-rings or snap ring grooves, undercut bores and the like. Examples of such devices are disclosed in U.S. Pat. No. 4,610,090 to Brady, U.S. Pat. No. 4,397,092 to Marcyan and U.S. Pat. No. 2,791,033 to Walters, each of which generally disclose calipers wherein parallel beams define the caliper arms. In such arrangements, one of the caliper beams is typically pinned to plates extending from the other beam to permit pivotal motion relative thereto. In other words, each of the foregoing designs basically discloses pivotally mounting one beam to an intermediate component which in turn is mounted to another beam. In addition, each includes a separate handle and trigger component attachable to a beam.
Because such measuring devices are intended to measure extremely small dimensions, their accuracy can be affected by their construction and design. In this respect, each additional attachment or component of a caliper must be precisely designed and manufactured to insure operating accuracy in the final caliper. As will be appreciated, the cost of fabricating a traditional component increases the overall cost, as well as assembly costs of such calipers.
The present invention provides a caliper wherein a first caliper arm is pivotally mounted directly to a second caliper arm in a scissor-like fashion, so as to reduce the number of components required therein, and provides a bearing assembly for mounting the first caliper arm to the second caliper arm that reduces the relative lateral deflection of the free ends of the caliper arms.